In the past many combination tools have been taught which involve using the gripping action of pliers to not only grip but to cut, strip, lock onto, or other wise engage an object while at the same time using one or all of the distal ends of the pliers for use as another tool such as a wrench or screwdriver.
Although combination tools have been known for many years and have the advantages of convenience and lighter weight over separate tools to do the same jobs, they have generally achieved these advantages at the cost of efficiency for one or more of the specific tasks for which they are adapted. That is, in attempting to be jacks of all trades, they are rarely able to master even one. For example, the tools shown in U.S. Pat. Nos. 1,321,777 and 1,739,658 feature a screwdriver blade at the end of one of the handles of a pliers as also does design Pat. Nos. 281,216 and 255,529. Now as anyone who has used such a tool as a screwdriver will attest, this arrangement is far from satisfactory. The main drawback is the requirement that the user grip the sharp jaws of the pliers when applying pressure down on the screw to be driven.
Also, the prior art when using the handle of the pliers as a screwdriver have designed the handle with generally a curved handle which does not allow the screwdriver to engage the screw in a perpendicular manner but the pliers must be held at an angle and when used as a screwdriver the pliers end must swing through an arc in order to keep the screwdriver squarely in the fastener.
Pat. No. 3,946,453 approaches this problem by placing the screwdriver on one of the jaws of the pliers but now the depth of the handle is sacrificed and only surface screws can be addressed.
Also, the present inventors have on file an application No. 07/439,245 which addresses this problem, however, no means is provided in this application to lock the pliers in substantially a 90 degree angle to each other, or to allow the pliers to open to a substantially 180 degrees and provide retaining means to hold the pliers in this position.
Also the present inventors have on file an application No. 07/468,135 which teaches the partial locking of the plier members at substantially 90 degrees to each other by means of a ball-bearing and spring which is not a positive lock.